Preparation method of multi-functional marine engineering alloy

Abstract

The present disclosure discloses a preparation method of a multi-functional marine engineering alloy. Through the coupling of a multi-principal alloy structure, structural entropy, and temperature and powder metallurgy and heat treatment, mutual solubility between elements and free energy of an alloy system are regulated, Cu grain boundary segregation is eliminated, and uniform and dispersed nano-precipitation of the anti-fouling element Cu in corrosion-resistant and high-plasticity multi-principal alloys is realized. The preparation method is simple and controllable to operate, and the prepared material has plasticity higher than 75%, high yield strength, excellent corrosion resistance and anti-fouling property, and has important application prospects in the field of marine engineering.

What is claimed is: 
     
       1. A preparation method of a multi-functional marine engineering alloy, comprising the following steps:
 performing a mixed ball milling step comprising:
 weighing Co—Cr—Fe—Ni face-centered cubic (FCC)-based high-entropy alloy powder and Cu powder separately; 
 loading the weighed Co—Cr—Fe—Ni FCC-based high-entropy alloy powder and Cu powder into a ball milling tank for mixed ball milling; and 
 conducting drying treatment after the ball milling to obtain a mixed powder; 
 
 performing a high-temperature sintering step to promote mutual solubility, the high-temperature sintering step comprising:
 loading the obtained mixed powder into a graphite die, placing the graphite die in a spark plasma sintering (SPS) furnace; 
 conducting pressure sintering in a vacuum environment or under protection of inert gas at 1,000-1,500° C. to obtain a sintered material; and 
 cooling the sintered material to a room temperature with the furnace after the sintering; and 
 
 performing a heat treatment step to induce nano-precipitation, the heat treatment step comprising:
 placing the sintered material in a heat treatment furnace; 
 conducting heat preservation heat treatment at 650-950° C.; and 
 water cooling or cooling with the furnace after the heat treatment to obtain the multi-functional marine engineering alloy, 
 wherein components of the Co—Cr—Fe—Ni FCC-based high-entropy alloy are in equimolar or nearly molar ratios and have molar percentages of Co(a)Cr(b)Fe(c)Ni(d), a+b+c+d=100, 30≥a≥20, 30≥b≥20, 30≥c≥20, 30≥d≥20, and 
 a percentage of the Cu powder in the mixed powder of the Co—Cr—Fe—Ni FCC-based high-entropy alloy powder and the Cu powder is 5-20 wt. %. 
 
 
     
     
       2. The preparation method of a multi-functional marine engineering alloy according to  claim 1 , wherein the Co—Cr—Fe—Ni FCC-based high-entropy alloy powder is obtained by atomizing the Co—Cr—Fe—Ni FCC-based high-entropy alloy, is spherical, and has a particle size of 15-100 μm. 
     
     
       3. The preparation method of a multi-functional marine engineering alloy according to  claim 1 , wherein the Cu powder has a purity greater than 99.9% and a particle size of 5-50 μm, and a percentage of the Cu powder in the mixed powder of the high-entropy alloy powder and the Cu powder is 5-20 wt. %. 
     
     
       4. The preparation method of a multi-functional marine engineering alloy according to  claim 1 , wherein conditions for the ball milling are as follows: a ball-to-powder ratio of (1-3): 1 and mixing for 10-15 h at 100-350 r/min. 
     
     
       5. The preparation method of a multi-functional marine engineering alloy according to  claim 1 , wherein conditions for the sintering comprise:
 an atmosphere in the furnace that is vacuumed to 5×10 −3 -10 Pa, or the furnace is filled with argon gas to 100-1,000 Pa, and 
 wherein the graphite die is pressurized up and down until a sample is under 30-50 MPa, a sintering holding time is 3-15 min, a heating rate from the room temperature to 1,000° C. is 30-50° C./min, and a heating rate for temperatures greater than 1,000° C. is 10-20° C./min. 
 
     
     
       6. The preparation method of a multi-functional marine engineering alloy according to  claim 1 , wherein conditions for the heat treatment are as follows: a heating rate of 5-20° C./min and a holding time of 5-50 h.